The present invention relates to a printing apparatus such as a printer, a typewriter or a computer terminal, which is provided with a carriage that has a printing mechanism facing a platen and operable to perform a printing operation and is reciprocally movable along a printing line on the platen, a control unit provided on a printer body for sending a control signal to the printing mechanism of the carriage for a printing operation, and an elongated signal-transmitting flexible member for electrically connecting the carriage and the control unit.
In conventional printing apparatuses of this type, a plurality of wires, connected to a character selection motor, a solenoid for a printing hammer, etc. which are mounted to the carriage, are fitted in a bundle in a flexible protective tube to be a cable serving as the elongated signal transmitting flexible member, and this cable extends on a movable path of the carriage and is connected at its one end to a control circuit board constituting the control unit. In this case, both end portions with some length of the protective tube for the cable are firmly fixed respectively to one outer side face of the carriage and the bottom of a case for the printing apparatus, through clamps by means of attaching means such as screws.
The reason for employing the above connection structure where the cable is fixed at one end portion with some length to the carriage and at the other end portion also with some length to the control unit, is to prevent the cable from being disconnected or damaged at the connecting sections, which disconnection or damage is very likely to occur when these end portions of the cable are excessively bent or pulled.
However, according to the conventional printing apparatuses, particularly, that end portion of the protective tube which is fixed to the carriage always faces in a fixed direction, so that when the carriage moves within its movable range, the cable is bent with a very small bending radius particularly as the carriage reaches either end position of the movable range. This bending action applies an excessive bending stress to the wires of the cable and the protective tube, thus deteriorating their wearability. And the bending resistances of the wires and the protective tube increase the moving load of the carriage.
As such a cable, there is a thin flat, flexible belt type having a number of wires, but this belt is expensive so as to increase the manufacturing cost of the printing apparatuses and junction board and a connector needs to be provided under the movable region of the carriage.